JPH04112412A - Manufacture of ferro-electric thin film - Google Patents
Manufacture of ferro-electric thin filmInfo
- Publication number
- JPH04112412A JPH04112412A JP2228362A JP22836290A JPH04112412A JP H04112412 A JPH04112412 A JP H04112412A JP 2228362 A JP2228362 A JP 2228362A JP 22836290 A JP22836290 A JP 22836290A JP H04112412 A JPH04112412 A JP H04112412A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- reaction
- ferro
- solution
- components
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000010409 thin film Substances 0.000 title claims abstract description 52
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 10
- 238000006243 chemical reaction Methods 0.000 claims abstract description 29
- 239000000758 substrate Substances 0.000 claims abstract description 15
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 10
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 9
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 8
- 229910052745 lead Inorganic materials 0.000 claims abstract description 6
- 239000011248 coating agent Substances 0.000 claims description 14
- 238000000576 coating method Methods 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 11
- 239000010408 film Substances 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 4
- 239000005416 organic matter Substances 0.000 claims description 2
- 239000011541 reaction mixture Substances 0.000 claims description 2
- 230000000536 complexating effect Effects 0.000 claims 2
- 150000001875 compounds Chemical class 0.000 abstract description 10
- 239000000126 substance Substances 0.000 abstract description 8
- 239000007788 liquid Substances 0.000 abstract description 4
- 229910020289 Pb(ZrxTi1-x)O3 Inorganic materials 0.000 abstract 1
- 229910020273 Pb(ZrxTi1−x)O3 Inorganic materials 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 24
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 18
- 238000010304 firing Methods 0.000 description 10
- 238000010438 heat treatment Methods 0.000 description 8
- 239000010936 titanium Substances 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 239000002904 solvent Substances 0.000 description 7
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 238000009835 boiling Methods 0.000 description 6
- 239000000470 constituent Substances 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 239000002131 composite material Substances 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 4
- 230000021615 conjugation Effects 0.000 description 4
- 229940046892 lead acetate Drugs 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- XNWFRZJHXBZDAG-UHFFFAOYSA-N 2-METHOXYETHANOL Chemical compound COCCO XNWFRZJHXBZDAG-UHFFFAOYSA-N 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- KQNKJJBFUFKYFX-UHFFFAOYSA-N acetic acid;trihydrate Chemical compound O.O.O.CC(O)=O KQNKJJBFUFKYFX-UHFFFAOYSA-N 0.000 description 3
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 description 3
- BSDOQSMQCZQLDV-UHFFFAOYSA-N butan-1-olate;zirconium(4+) Chemical compound [Zr+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] BSDOQSMQCZQLDV-UHFFFAOYSA-N 0.000 description 3
- 238000002425 crystallisation Methods 0.000 description 3
- 230000008025 crystallization Effects 0.000 description 3
- 150000002611 lead compounds Chemical class 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 238000003541 multi-stage reaction Methods 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 150000001735 carboxylic acids Chemical class 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000003980 solgel method Methods 0.000 description 2
- VXUYXOFXAQZZMF-UHFFFAOYSA-N titanium(IV) isopropoxide Chemical compound CC(C)O[Ti](OC(C)C)(OC(C)C)OC(C)C VXUYXOFXAQZZMF-UHFFFAOYSA-N 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- -1 acetate trihydrate lead oxide Chemical compound 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- AGZCHLPJCXXPDM-UHFFFAOYSA-N dibutoxylead Chemical compound [Pb+2].CCCC[O-].CCCC[O-] AGZCHLPJCXXPDM-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005621 ferroelectricity Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- XPGAWFIWCWKDDL-UHFFFAOYSA-N propan-1-olate;zirconium(4+) Chemical compound [Zr+4].CCC[O-].CCC[O-].CCC[O-].CCC[O-] XPGAWFIWCWKDDL-UHFFFAOYSA-N 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000010405 reoxidation reaction Methods 0.000 description 1
- 238000004626 scanning electron microscopy Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、キャパシター、メモリー素子、センサー等に
利用可能な強誘電体薄膜の製造方法に関するものである
。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a ferroelectric thin film that can be used for capacitors, memory devices, sensors, etc.
［従来の技術］
従来、鉛、ジルコニウム、チタン系酸化物（以下ＰＺＴ
と略称する）等の強誘電体薄膜の製造方法として、スパ
ッタリング法や真空蒸着法、更にゾル・ゲル法が用いら
れている。これらの方法においては、得られる薄膜を構
成する成分の粒径を制御する方法として、得られた薄膜
を焼成する方法、或いは薄膜をアニールする際の温度お
よび時間を調節することによる制御方法であった。近時
、強誘電体薄膜の利用範囲が拡大するにつれて、薄膜の
基板として用いられる材料も種々のものが用いられるよ
うになってきた。[Conventional technology] Conventionally, lead, zirconium, titanium oxide (hereinafter referred to as PZT)
The sputtering method, the vacuum evaporation method, and the sol-gel method are used as methods for manufacturing ferroelectric thin films such as (hereinafter referred to as ferroelectric thin films). In these methods, the particle size of the components constituting the obtained thin film is controlled by firing the obtained thin film or by adjusting the temperature and time when annealing the thin film. Ta. In recent years, as the scope of use of ferroelectric thin films has expanded, various materials have come to be used as substrates for thin films.
しかし、上記したように薄膜の構成成分の粒径制御方法
が加熱による方法である以上、基板の選択によっては制
御の際の加熱温度に限りかあり、そのため、広い範囲に
亘り任意に粒径を制御することが困難であった。However, as mentioned above, since the method of controlling the particle size of the constituent components of a thin film is by heating, there is a limit to the heating temperature during control depending on the selection of the substrate. It was difficult to control.
［発明が解決しようとする課題］
前記した、薄膜の製法の内ゾル・ゲル法は、比較的粒径
の小さい強誘電体薄膜を得易いが、強誘電体は必要以上
に粒径が小さすぎると、材質本来の特性を引き出すこと
が困難である。[Problem to be solved by the invention] Among the thin film manufacturing methods described above, the sol-gel method can easily obtain a ferroelectric thin film with a relatively small grain size, but the grain size of the ferroelectric is too small than necessary. Therefore, it is difficult to bring out the original characteristics of the material.
本発明の目的は、前記問題点を解決し、同一の焼成条件
によっても任意に粒径を制御することが可能な薄膜の製
造方法を提供するものである。An object of the present invention is to solve the above-mentioned problems and to provide a method for manufacturing a thin film that allows the grain size to be arbitrarily controlled even under the same firing conditions.
５課題を解決するための手段］
本発明者らは、強誘電体薄膜の製造方法を鋭意検討した
結果、一般式Ｐｂ（Ｚｒ、 Ｔｔ＋ −）０３（ただし
０≦ｘ≦１）で表わされる強誘電体薄膜の製造に際し、
Ｐｂ ＳＴｉ、Ｚｒ成分と有機物との複合化反応混合液
から、これらの複合化反応により生成する複合化物以外
の反応生成物量の１７４〜３／４を反応系から除去した
ものを基板上に塗布し、塗布面を焼成することにより、
得られる薄膜成分の粒径を０．０２〜１μｍの範囲で任
意に制御することが可能であることを見出だし本発明を
完成した。[Means for Solving 5 Problems] As a result of intensive study on the manufacturing method of ferroelectric thin films, the present inventors have determined that the strong When manufacturing dielectric thin films,
From the composite reaction mixture of Pb STi, Zr components and organic matter, 174 to 3/4 of the amount of reaction products other than the composite produced by these composite reactions was removed from the reaction system, and the mixture was applied onto a substrate. , by firing the coated surface,
The present invention was completed based on the discovery that the particle size of the obtained thin film component can be arbitrarily controlled within the range of 0.02 to 1 μm.
以下、その詳細について説明する。The details will be explained below.
本発明では、前記した一般式で表わされる組成となるよ
うにＰｂ、 Ｚｒ、 Ｔｉ成分を有機物と混合し、得ら
れた混合溶液を加熱することによってこれらの複合化合
物としたものを基板上に塗布するが、ここで用いるＰｉ
ｅｒ、 Ｚｒ、 Ｔｉ成分は例えば次のＡ−Ｃ群で表さ
れるものである。In the present invention, Pb, Zr, and Ti components are mixed with an organic substance so as to have a composition represented by the general formula described above, and a composite compound of these is applied on a substrate by heating the resulting mixed solution. However, Pi used here
The er, Zr, and Ti components are represented by the following A-C group, for example.
また、これらと混合する有機物は下記り群に示す溶媒か
ら選択されるものである。Further, the organic substance to be mixed with these is selected from the solvents shown in the following group.
Ａ群：酢酸鉛・３水和物 酸化鉛 Ｐｂ（ＯＲ） ２ Ｂ群： Ｔｉ（ＯＲ−） 。Group A: Lead acetate trihydrate lead oxide Pb (OR) 2 Group B: Ti (OR-).
Ｃ群： Ｚｒ（ＯＲ−）、＋
（Ｒ５Ｒ−１Ｒ−′は炭素数２以上のアルキル基）
Ｄ群： ｔｌＯｃＨ２ＣＨ２０Ｒ
Ｒ２Ｃ００Ｈ
１？”０Ｈ
（Ｒ’ 、Ｒ’ 、Ｒ’は炭素数１以上のアルキル基）
本発明で用いる塗布液の調製は、まず、Ａ群より選択さ
れる少なくとも一種の鉛化合物を、Ｄ群より選択される
少なくとも一種の有機物中に混合する、この時鉛化合物
が結晶水を含む場合には加熱によりそれを除去しておく
ことが好ましい。又用いるＤ群より選択される少なくと
も一種の有機物の量は少なくともＡ−Ｃ群の化合物と反
応し得る量以上用いれば良い。この混合溶液中にＢ群お
よびＣ群より選択される少なくとも一種のＴｉおよびＺ
ｒアルコキシドを所定量（前記一般式で表される化学量
論量）添加した後攪拌しながら加熱し各成分間で−の複
合化反応例えば縮重合反応によりＰｂ、 Ｚｒ、 Ｔｉ
金属元素を含む複合化物溶液とする。Group C: Zr(OR-), + (R5R-1R-' is an alkyl group having 2 or more carbon atoms) Group D: tlOcH2CH20R R2C00H 1? "0H (R', R', R' are alkyl groups having 1 or more carbon atoms) To prepare the coating solution used in the present invention, first, at least one lead compound selected from Group A is mixed with at least one lead compound selected from Group D. At this time, if the lead compound contains crystal water, it is preferable to remove it by heating.Also, the amount of the at least one organic substance selected from Group D used should be at least It is sufficient to use at least one of Ti and Z selected from Groups B and C in the mixed solution.
After adding a predetermined amount (a stoichiometric amount expressed by the above general formula) of r-alkoxide, it is heated while stirring, and a compounding reaction of -, such as a polycondensation reaction, is performed between each component to form Pb, Zr, and Ti.
A composite solution containing metal elements is prepared.
この際の加熱条件は５０℃から前記り群の化合物の沸点
までの温度で、０．５〜２４時間である。本発明はこの
Ｐｂ、、Ｚｒ、 Ｔｉ金属元素を含む複合化合物溶液を
基板上への塗布液とする。The heating conditions at this time are a temperature from 50° C. to the boiling point of the above-mentioned group of compounds for 0.5 to 24 hours. In the present invention, this composite compound solution containing metal elements Pb, Zr, and Ti is used as a coating solution on a substrate.
本発明における複合化反応は、構成成分であるｐ’ｏ、
Ｚｒ、 Ｔｉが、酸素またはＣ００を介して連結した
構造とするためであり、本発明は、この連結の度合いを
調節することにより薄膜の構成成分の粒径を制御するこ
とが特徴である。The conjugation reaction in the present invention includes p'o, which is a constituent component,
This is to create a structure in which Zr and Ti are connected via oxygen or C00, and the present invention is characterized in that the grain size of the constituent components of the thin film is controlled by adjusting the degree of this connection.
この際の連結の度合いの調節は、前記複合化反応中にお
いて又は反応後に、複合化物以外の反応成分の反応系か
らの除去量を調節することにより制御する。この成分は
、前記したＡ、Ｂ５Ｃ５Ｄ群の反応により生成するもの
で、例えばアルコール、カルボン酸、エステルなどであ
る。The degree of linkage at this time is controlled by adjusting the amount of reaction components other than the complex to be removed from the reaction system during or after the complex reaction. This component is produced by the reaction of the above-mentioned A, B5C5D group, and includes, for example, alcohol, carboxylic acid, and ester.
反応系からこれらを除去する際の除去量は、除去量が少
ないと反応が充分に進行せず、この反応溶液を用いて目
的とする強誘電体を形成する際に高い処理温度が必要と
なり、又、過度に除去すると反応溶液の粘度が上昇し、
後の工程における操作が容易でなくなる。本発明では、
複合化物以外の反応生成物量の１７４〜３／４を除去す
ることが必要である。When removing these from the reaction system, if the amount removed is small, the reaction will not proceed sufficiently, and a high processing temperature will be required when forming the desired ferroelectric material using this reaction solution. In addition, excessive removal will increase the viscosity of the reaction solution,
This makes operations in subsequent steps difficult. In the present invention,
It is necessary to remove 174 to 3/4 of the amount of reaction products other than the complex.
前記に示した反応生成物の除去量の範囲において、この
反応溶液を用い、後の処理を経て得られる薄膜構成成分
の粒径は、例えば膜の熱処理温度を６５０℃に固定した
場合、除去量が生成量の１７４量で約０．０２〜０．０
５μｍ 、 １／２量でＯ，ｂｚｍ 、 ３／４量で１
μｍ程度となる。Within the range of the amount of reaction product removed as shown above, the particle size of the thin film component obtained through the subsequent treatment using this reaction solution is, for example, when the heat treatment temperature of the film is fixed at 650°C, the amount of removal is is approximately 0.02 to 0.0 in the amount of 174 produced.
5 μm, 1/2 amount is O, bzm, 3/4 amount is 1
It is about μm.
本発明においてＤ群にあげた有機物は、沸点が１００℃
〜１８０℃のものが好ましく、沸点が１００℃より低い
ものを用いると、塗布液を基板へ塗布する際、塗布中に
溶液の濃度変化が起き易く、厚みむらの原因となる。ま
た、過度に沸点が高いものでは、基板に塗布した後の乾
燥工程で溶媒か膜面に残存し易く薄膜面に細孔か生ずる
原因となる。In the present invention, the organic substances listed in Group D have a boiling point of 100°C.
A solution having a boiling point of 180° C. to 180° C. is preferable, and if a solution having a boiling point lower than 100° C. is used, the concentration of the solution tends to change during coating, causing thickness unevenness. Furthermore, if the boiling point is too high, the solvent tends to remain on the film surface during the drying process after being applied to the substrate, causing pores to form on the thin film surface.
又、Ａ〜Ｃ群にあげた各構成成分の原料は前記した複合
化反応により生成するアルコール、カルボン酸、又、こ
れらからのエーテル、エステル等の反応生成物の沸点が
Ｄ群より選択した有機物よりも低い生成物となるように
選択するのか、複合化反応の進行を容易にし、これを用
いて目的とする薄膜を得る上で好ましい。In addition, the raw materials for each of the constituent components listed in Groups A to C are alcohols and carboxylic acids produced by the above-mentioned complex reaction, and organic substances selected from Group D whose boiling point is the reaction product such as ether and ester from these. It is preferable to select such a product that the amount of the product is lower than that in order to facilitate the progress of the composite reaction and use this to obtain the desired thin film.
また、Ｂおよび０群より選択されるＴｉおよびＺｒに関
しては、これらのアルコキシドを用いる場合は、複合化
反応が同時に起こり易くするために、同種のアルコキシ
ル基を選択して用いるのが好ましい。なお、Ａ−Ｃおよ
びＤ群の中から二種以上を選択して用いても何等さしつ
かえない。Regarding Ti and Zr selected from Groups B and 0, when using these alkoxides, it is preferable to select and use alkoxyl groups of the same type in order to facilitate simultaneous conjugation reactions. Note that there is no problem even if two or more types are selected and used from groups A to C and D.
本発明では、上記した方法で得られた塗布液を基板上に
塗布し薄膜を形成する。実際の塗布の際の塗布液は複合
化物の濃度として０．３〜１モル％となるように前記り
群の化合物で調節して用いる。In the present invention, the coating liquid obtained by the method described above is applied onto a substrate to form a thin film. The coating solution used in actual coating is adjusted with the above-mentioned compounds so that the concentration of the composite compound is 0.3 to 1 mol %.
コノ際ノ薄膜の形成方法はスピンコード法、塗布溶液中
に基板を浸漬して引き上げるデイツプ法あるいはスプレ
ーによる塗布法などが用いられる。The thin film can be formed by a spin code method, a dip method in which the substrate is immersed in a coating solution and pulled up, or a spray coating method.
次に、基板上に形成した薄膜を乾燥し、非晶質薄膜とす
る。この乾燥工程は薄膜と基板との付着強度の面から考
えると、瞬時に行うのか好ましく、通常所定の乾燥温度
で一分以内加熱することか好ましい。故にホットプレー
ト上において行うのか好ましい。この際の乾燥温度は過
度に高いと薄膜成分が結晶化し、冷却時に立方晶から正
方晶への相転移が起こりクラック発生等の原因となる。Next, the thin film formed on the substrate is dried to form an amorphous thin film. In view of the strength of adhesion between the thin film and the substrate, this drying step is preferably carried out instantaneously, and usually heated at a predetermined drying temperature within one minute. Therefore, it is preferable to perform it on a hot plate. If the drying temperature at this time is too high, the thin film components will crystallize, and phase transition from cubic to tetragonal will occur during cooling, causing cracks and the like.
又、過度に低いと溶媒が完全に除去できないので２００
℃〜４５０℃の範囲で行うのか好ましい。Also, if it is too low, the solvent cannot be completely removed, so the
It is preferable to carry out the reaction at a temperature in the range of .degree. C. to 450.degree.
次に上記非晶質薄膜を焼成して、ＰＺＴ強誘電体薄膜と
する。この焼成工程は、−回の焼成の際の薄膜の厚さを
０，５μｍ以下とすることが好ましく、例えば非晶質薄
膜を基板ごと電気炉に入れ１〜２０’Ｃ／ｍｉｎの速度
で５００℃以上まで昇温し、その温度で１分〜４時間保
持した後、昇温速度と同程度の速度で冷却して行う。こ
の際、−回の焼成による厚さが０５μｍより厚いと、焼
成による膜の収縮が大きくクラック発生の原因となる。Next, the amorphous thin film is fired to form a PZT ferroelectric thin film. In this firing process, the thickness of the thin film during the second firing is preferably 0.5 μm or less. For example, the amorphous thin film is placed in an electric furnace together with the substrate and heated at a speed of 1 to 20 C/min to 500 μm or less. The temperature is raised to .degree. C. or higher, maintained at that temperature for 1 minute to 4 hours, and then cooled at a rate comparable to the temperature increase rate. At this time, if the thickness after the second firing is greater than 0.5 μm, the shrinkage of the film due to the firing will be large and cause cracks to occur.
又より厚い膜を必要とする場合には、前記の塗布、乾燥
、焼成の工程を繰り返すことにより所望の厚さの薄膜を
得ることができる。又、焼成の際の昇温、降温速度は、
上記した範囲内であれは特に問題となることはないが、
降温速度を過度に速くするとキュリー温度での立方晶か
ら正方晶への相転移か急激に起こり、クラック発生の原
因となる。また焼成温度は５００°Ｃより低い温度では
膜を構成する酸化物がペロブスカイト型構造とならず従
って強誘電性を示さず、更に、熱分解により生成する炭
素質が薄膜中に残留し、膜の誘電損失の増大の原因とな
る。If a thicker film is required, a thin film of the desired thickness can be obtained by repeating the coating, drying, and baking steps described above. Also, the rate of temperature rise and fall during firing is as follows:
There is no particular problem within the above range, but
If the cooling rate is excessively high, a phase transition from cubic to tetragonal at the Curie temperature will occur rapidly, causing cracks to occur. In addition, if the firing temperature is lower than 500°C, the oxide that makes up the film will not form a perovskite structure and therefore will not exhibit ferroelectricity.Furthermore, carbonaceous matter produced by thermal decomposition will remain in the thin film, causing the film to deteriorate. This causes an increase in dielectric loss.
本発明での焼成工程における雰囲気は、基本的には大気
中あるいは酸素気流中で行うのが好ましいが、例えば下
部電極として使用する金属か酸化され易い場合にはアル
ゴン等の不活性ガスあるいは窒素気流中でまず焼成を行
い、次いで、その焼成温度以下の温度で再酸化処理を行
うことも可能である。The atmosphere in the firing step in the present invention is basically the air or an oxygen stream, but if the metal used as the lower electrode is easily oxidized, an inert gas such as argon or a nitrogen stream may be used. It is also possible to first carry out calcination in the medium and then perform reoxidation treatment at a temperature below the calcination temperature.
Ｌ発明の効果］
以上で説明したように本発明は、基板への塗布液の調製
工程において、その構成成分の複合化反応により生成す
る複合化以外の反応生成物量の１／４〜３／４の量を反
応系から除去した反応液を用いることにより、得られる
薄膜構成成分の粒径を、同一の焼成条件においても０．
０２〜１μｍの範囲で任意に選択することか可能であり
、薄膜構成成分の粒径による膜の強誘電特性の制御を行
うことができる。[Effects of the Invention] As explained above, the present invention provides 1/4 to 3/4 of the amount of reaction products other than conjugation produced by the conjugation reaction of the constituent components in the process of preparing a coating liquid for a substrate. By using a reaction solution from which an amount of .
It is possible to arbitrarily select the diameter within the range of 0.02 to 1 μm, and the ferroelectric properties of the film can be controlled by the particle size of the thin film constituents.
従って、広い範囲の種類の基板に適応可能である。Therefore, it is applicable to a wide range of types of substrates.
［実施例および比較例］
実施例１
酢酸鉛・３水和物１１３．７９９ｇをエチレングリコー
ルモノメチルエーテル２００ｍ１中に溶解した後１２０
℃まで加熱して結晶水の除去を行った。除去後９０℃以
下まで冷却し酢酸１８ｇを添加し、さらにジルコニウム
プロポキシド５２．０８０ｇ、チタニウムイソプロポキ
シド４０．０７６ｇを添加し再び加熱して反応系全体の
体積が１５０ｍ１になるまで溶媒を蒸発除去した後室温
まで冷却してＰＺＴ濃度で１．５ｍｏｌ／１となるよう
エチレングリコールモノメチルエーテルを添加して溶液
を調製した。この溶液を１６．７ｍ１分取し、エチレン
グリコールモノメチルエーテル８、３ｍｌ、水０．９ｍ
ｌを添加して塗布液とし、これをスピンコーターで白金
をコーティングしたシリコンウェハー上に塗布し３００
℃で乾燥し非晶質薄膜を得た。この非晶質薄膜を６５０
℃、２０分焼成を行い結晶化させＰＺＴ薄膜を作製した
。得られた薄膜の粒径は走査型電子顕微鏡観察の結果０
．１μｍであった。[Examples and Comparative Examples] Example 1 After dissolving 113.799 g of lead acetate trihydrate in 200 ml of ethylene glycol monomethyl ether,
The water of crystallization was removed by heating to ℃. After removal, cool to below 90°C, add 18 g of acetic acid, further add 52.080 g of zirconium propoxide and 40.076 g of titanium isopropoxide, and heat again to evaporate and remove the solvent until the total volume of the reaction system becomes 150 ml. After that, the mixture was cooled to room temperature, and ethylene glycol monomethyl ether was added so that the PZT concentration was 1.5 mol/1 to prepare a solution. Take 16.7 ml of this solution, add 8.3 ml of ethylene glycol monomethyl ether, and 0.9 ml of water.
1 was added to form a coating solution, and this was applied onto a silicon wafer coated with platinum using a spin coater for 300 min.
It was dried at ℃ to obtain an amorphous thin film. This amorphous thin film was
C. for 20 minutes to crystallize and produce a PZT thin film. As a result of scanning electron microscopy, the particle size of the obtained thin film was 0.
．． It was 1 μm.
実施例２
酢酸鉛・３水和物１８．９６７ｇ、を酢酸１０ｍ１中に
溶解した後１２０℃まで加熱して結晶水の除去を行った
。除去後、９０℃以下まで冷却しジルコニウムブトキシ
ド１０．１６７ｇ、チタニウムブトキシド７、９９８ｇ
を添加し再び加熱して反応系の体積が２０１ｕ１になる
まで溶媒を蒸発除去し、この溶液に酢酸６２ｍ１、水１
３ｍ１添加して塗布液とし、これをスピンコーターで白
金をコーティングしたシリコンウェハーに塗布し３００
℃で乾燥し非晶質薄膜を得た。さらに実施例１と同様に
して焼成を行いＰＺＴ薄膜としたところ、得られた薄膜
の粒径は０．０２μｍであった。Example 2 18.967 g of lead acetate trihydrate was dissolved in 10 ml of acetic acid and heated to 120° C. to remove water of crystallization. After removal, cool to 90°C or below to obtain 10.167 g of zirconium butoxide and 7.998 g of titanium butoxide.
was added and heated again to evaporate the solvent until the volume of the reaction system became 201 u1. To this solution, 62 ml of acetic acid and 1 ml of water were added.
3ml was added to make a coating solution, and this was applied to a silicon wafer coated with platinum using a spin coater.
It was dried at ℃ to obtain an amorphous thin film. Further, baking was performed in the same manner as in Example 1 to form a PZT thin film, and the grain size of the obtained thin film was 0.02 μm.
実施例３
鉛ブトキシド（トルエン溶液） ４８．５４４ｇをｎ
−ブタノール１８ｇ中に添加した後１１０℃まで加熱し
てトルエンの除去を行った。除去後、９０℃以下まで冷
却し酢酸２０ｇを添加し、さらにジルコニウムブトキシ
ド１０．１６７ｇ、チタニウムブトキシド７、９９８ｇ
を添加し再び加熱して反応系の体積が５９ｍ１になるま
で溶媒を蒸発除去し、この溶液にブタノール５０ｍ１．
水１．８ｍｌ添加して塗布液とし、これをスピンコータ
ーでシリコンウェハーに塗布し３００℃で乾燥し非晶質
薄膜を得た。さらに実施例１と同様にして焼成を行いＰ
ＺＴ薄膜としたところ、得られた薄膜の粒径・は０．０
５μｍであった。Example 3 Lead butoxide (toluene solution) 48.544 g
- After adding it to 18 g of butanol, it was heated to 110°C to remove toluene. After removal, cool to below 90°C, add 20g of acetic acid, and further add 10.167g of zirconium butoxide and 7.998g of titanium butoxide.
was added and heated again to evaporate the solvent until the volume of the reaction system became 59 ml, and to this solution was added 50 ml of butanol.
1.8 ml of water was added to obtain a coating solution, which was coated onto a silicon wafer using a spin coater and dried at 300° C. to obtain an amorphous thin film. Further, baking was performed in the same manner as in Example 1.
When a ZT thin film was formed, the grain size of the obtained thin film was 0.0.
It was 5 μm.
実施例４
酢酸鉛・３水和物３６．ＯＯｇ 、を酢酸３５ｍ１中に
溶解した後１２０℃まで加熱して結晶水の除去を行った
。除去後、９０℃以下まで冷却しジルコニウムブトキシ
ド１６．６０ｇ、チタニウムブトキシド６、５０ｇを添
加し再び加熱して反応系の体積が２０ｍ１になるまで溶
媒を蒸発除去し、この溶液に酢酸６２ｍ１ 。Example 4 Lead acetate trihydrate 36. After dissolving OOg in 35 ml of acetic acid, the solution was heated to 120°C to remove water of crystallization. After the removal, it was cooled to below 90°C, 16.60 g of zirconium butoxide and 6.50 g of titanium butoxide were added, and the solvent was evaporated off by heating again until the volume of the reaction system became 20 ml, and 62 ml of acetic acid was added to this solution.
水１８ｍ１添加して塗布液とし、これを実施例３と同様
にして薄膜化し３００℃で乾燥し非晶質薄膜を得た。さ
らに実施例１と同様にして焼成を行いＰＺＴ薄膜とした
ところ、得られた薄膜の粒径は１μｍであった。18 ml of water was added to obtain a coating solution, which was formed into a thin film in the same manner as in Example 3 and dried at 300°C to obtain an amorphous thin film. Further, baking was performed in the same manner as in Example 1 to form a PZT thin film, and the grain size of the obtained thin film was 1 μm.
Claims (1)
０≦ｘ≦１）で表わされる強誘電体薄膜の製造に際し、
Ｐｂ、Ｔｉ、Ｚｒ成分と有機物との複合化反応混合液か
ら、これらの複合化反応により生成する複合化物以外の
反応生成物量の１／４〜３／４を反応系から除去したも
のを基板上に塗布し、塗布面を焼成することを特徴とす
る強誘電体薄膜の製造方法。When manufacturing a ferroelectric thin film represented by the general formula Pb(Zr_xTi_1_x)O_3 (0≦x≦1),
From the complexing reaction mixture of Pb, Ti, and Zr components and organic matter, 1/4 to 3/4 of the amount of reaction products other than the complexes produced by these complexing reactions is removed from the reaction system, and then the mixture is placed on the substrate. 1. A method for producing a ferroelectric thin film, the method comprising coating the film on the surface of the ferroelectric film and baking the coated surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22836290A JP3013411B2 (en) | 1990-08-31 | 1990-08-31 | Manufacturing method of ferroelectric thin film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22836290A JP3013411B2 (en) | 1990-08-31 | 1990-08-31 | Manufacturing method of ferroelectric thin film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04112412A true JPH04112412A (en) | 1992-04-14 |
| JP3013411B2 JP3013411B2 (en) | 2000-02-28 |
Family
ID=16875273
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22836290A Expired - Fee Related JP3013411B2 (en) | 1990-08-31 | 1990-08-31 | Manufacturing method of ferroelectric thin film |
Country Status (1)
| Country | Link |
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| JP (1) | JP3013411B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996029725A1 (en) * | 1995-03-21 | 1996-09-26 | Northern Telecom Limited | Ferroelectric dielectric for integrated circuit applications at microwave frequencies |
| JPH11315041A (en) * | 1998-02-12 | 1999-11-16 | Samsung Display Devices Co Ltd | Metal oxide precursor composition and its production |
-
1990
- 1990-08-31 JP JP22836290A patent/JP3013411B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996029725A1 (en) * | 1995-03-21 | 1996-09-26 | Northern Telecom Limited | Ferroelectric dielectric for integrated circuit applications at microwave frequencies |
| US5886867A (en) * | 1995-03-21 | 1999-03-23 | Northern Telecom Limited | Ferroelectric dielectric for integrated circuit applications at microwave frequencies |
| JPH11315041A (en) * | 1998-02-12 | 1999-11-16 | Samsung Display Devices Co Ltd | Metal oxide precursor composition and its production |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3013411B2 (en) | 2000-02-28 |
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